Method of forming a seam



Oct 17, 1939. O DALLER 2,176,584

' METHOD OF Fdnmme A SEAM Filed May 6, 1953 INVENT OR ATTORNEYS Patented a. 17, v1939 IMETHOD 0F FORMING SEAM Adrian o. Daller, Dennisport, assignor as Utility Packages, Inc., a corporation of New York Application May 6, 1933, Serial No. 669,662

lclaim.

This invention relates to containers and to a method of constructing the same, and specifically to moisture-proof containers.

In general, it is an object of the invention to provide a device of the character described, which will efficiently perform the purpose for which it is intended, which is simple and economical of construction, which can be safely relied upon, and which can be readily manufactured m and assembled.

Another object of the invention is to provide a coated moisture-proof container which is tightly sealed without using a solvent for the moisture-' proof coating.

1;; Another object is to provide a moisture-proof container that may be sealed after filling without setting up objectionable bouquets and without the application of heat.

Another object is to provide a method of forming a moisture-proof container.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the article possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims. v

For a fuller' understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawing, in

' which:

Fig. 1 is a plan view of one form of blank from which a container may be fabricated in accordance with the invention;

Fig.2 is aperspective view of a container, un-

4 filled and not completely sealed, and made from the blank shown in Fig. 1; and

Fig. 3 is a perspective view of the container shown in Fig. 2, the seal, however, being complete. y

In the drawing the numeral i0 denotes a blank from which a container is to be made. The container may be used simply as a package or it may comprise the lining or the outer wrapping for some other container. Any desired material may be used and it is preferably moisture-proof,

for example, waxed paper.

An adhesive is applied to certain portions of the blank, whereby, when the blank is folded against itself, a container is formed which may 5 have the shape of an open bag. These portions are shown as strips ll extending along at least part of the periphery of two edges of the blank.-

The adhesive used contains a latex, caoutchouc latex being particularly suitable. ,It is capable, in the fluid state, of adhering to most surfaces 5 and upon drying will continue to adhere thereto as .a water-repellent film. After it has been applied to a surface and dried out thereon it has very little tendency, if any, to adhere to another surface not so treated. It will, however, in such 10 a dried state, adhere to another similarly-treated surface, and two dried latex layers exhibit a relatively large force of cohesion.

A latex in which the colloidal rubber is about seventy-five per cent. and the water is about 15 twenty-five per cent. may be called a commercially normal concentration. If an uncoated surface of paper or other object is to be prepared for adhesion this normal latex may have any desired amount of water added. This addition may 20 amount to two hundred per cent. It is desirable that the adhesive be in such a state that it can be spread in any convenient. manner, as by a roller or brush. The concentration will depend obviously upon the circumstances, such as the 25 physical properties of the paper surface, the tension to which the adhesive seam is to be subjected, how rapidly the surface or seam is to be dried out, how much heatis available for drying, etc. It is essential that the final dried latex g0 1 film in the seam be substantial enough to withfound advisable to have heat present after the 40 latex is applied. The waxed surface itself may be heated, or the'latex, having been applied to the wax on one surface, may be pressed against another coated surface and caused to commingle therewith, by passing the assembly between heat- 46 ed means. In any event there should be suflicient heat to cause whatever amount of wax is present to become somewhat fluid and some-. what interspersed with the latex.

It is found advantageous in connection with coated surfaces to use a concentration of latex such that the latex will not roll up into globules.

If the coated surfaces with latex thereon are to be pressed together before the globules have had time to form, more water may be used. The

cent. of the normal latex when waxed surfaces are to be pressed together soon after the latex application. When, however, the coated surfaces with latex thereon are not to be pressed together until they have completely dried out the concentration may approach'that of the normal latex, in which'case it is spread'on more like a paste.

stabilizing agent, for example, one per cent. potassium hydroxide and two per cent. neutral soft soap.

' The odor of ammonia, arising as a natural concomitant of the vegetable matter or from ammonia added at the source to help maintain the colloid character, may be removed by stirring a suitable agent, such as trlethanolamine, intolthe latex and drawing oil the ammonia vapor. The former replaces the alkalinity of the latter and adds keeping properties. From one-half of one to one per cent. of the triethanolamine is sufllcient to maintain stability.

From five to ten per cent. of casein may be added to strengthen the adhesive properties and to lessen the cost. Ammonium hydroxide may add the alkalinity necessary to keep the latex and casein in solution. A certain amount of sodium hypochlorite increases tackiness. Methyl salicylate may be used as a deodorant and a mild germicide to prevent the decomposition of the casein.

Another satisfactory formula is:

. Per cent Normal later '65 Chalk or clay v i5 casein ammonia solution 20 Slightly variable.

Still another formula is:

- Per cent Normal latex 65 Clay 12 10% casein ammonia solution. 15 oxgall solution; 5

Zinc oxide 2 Sulphur =1 Plus a slight amount of anti-oxidant and accelerator.

pressed against that portion on the other face as the blank is folded, to form a seam having no exposed or free edge. r

The processis more quicklycarried out ifthe blank is folded before the strip dries, in which case the strip need'oniy extend along a portion of the periphery and the seam may be with or' without afreeedgq-flielatter formbelngshown inl 'lg.2. r

In the normal concentration there may be a Q surfacestogether.

water added may amount to one hundred per The adhesive may contain water in addition to that of the normal concentration as explained above. If the blank is made of waterproof material, or is waterproofed with a material such as wax, then.- heat must be present to permit the intermingling of the wax and the latex. It is desirable to continue the heating during the pressing of the seam in order that the water excess may dry out. The unfilled container is shown in Fig. 2.

Other strips l2 of the latex'adhesive are applied, with heat and before, folding, to those portions of the periphery of the blank which are to form the mouth of the container. In the event that time is to elapse between the preparing of the blank, the filling of the container and the A container so sealed is shown in Fig. 3.

If desired, dry stripping may be resorted to. In such event the material of the blank is not made moisture-proof in those portions to which the adhesive is to be appliedand the adhesive need not be heated to effect an adequate bond with the material of the blank.

Although the contour of the blank is shown as generally oblong and rectangulanit will be evident that the shape of the blank is immaterial as long as it may be folded into a container of the desired dimensions.

Since certain changes in carrying out the above process, and certain modifications in the article which embody the invention may be made without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is'also to be understood that the following claim is intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. I

Having describedmy invention, what I claim as new and desire to secure by Letters Patent, is:

The method of providing a water-proof seam between wax coated surfaces, comprising applying an adhesive containing latex to said surfaces,

heating said surfaces to cause said adhesive to form a mixture with the wax coating on said surfaces and to dry, and thereafter pressing said -ADRIANO.DALLER. 

